(a) Field of the Invention
The present invention relates to a method and an apparatus for setting a pilot subcarrier. In particular, the present invention relates to a method and an apparatus for setting a pilot subcarrier in an antenna for estimating a channel.
(b) Description of the Related Art
A communication system (hereinafter referred to as “OFDM system”) using an orthogonal frequency division multiplexing (OFDM) scheme or an orthogonal frequency division multiplexing access (OFDMA) scheme modulates data to be transmitted into a plurality of pilot subcarriers that are orthogonal to each other, and transmits the pilot subcarriers at the same time. Therefore, the OFDM system can prevent multipath interference incurring performance degradation in a mobile receiving environment.
However, the OFDM system should perform estimation and compensation of a channel in order to overcome a Doppler effect generated due to movement of a reception side and a weakness generated at the time of restoring data in a multiple path channel.
For this, the estimation and compensation of the channel, etc., are performed by using the pilot subcarrier that performs a midamble function. However, in the case of a channel having a large number of pilot subcarriers and a large frequency selection characteristic, a mean squared error (MSE) of the channel estimation occurs.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.